/* rabadr.c */

/*
 *  Copyright (C) 1989-2025  Alan R. Baldwin
 *
 *  This program is free software: you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation, either version 3 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
 *
 *
 * Alan R. Baldwin
 * 721 Berkeley St.
 * Kent, Ohio  44240
 * 
 * ported to the Rabbit2000 by
 * Ulrich Raich and Razaq Ijoduola
 * PS Division
 * CERN
 * CH-1211 Geneva-23
 * email: Ulrich dot Raich at cern dot ch
 */

/*
 * xerr messages and order fix Copyright (C) 1989-2021  Alan R. Baldwin
 * from ASxxxx 5.40
 */

/*
 * Extensions: P. Felber
 *
 * Altered by Leland Morrison to support rabbit 2000 
 *   and rabbit 4000 instruction sets (2011)
 */

#include "asxxxx.h"
#include "rab.h"

/*
 * Read an address specifier. Pack the
 * address information into the supplied
 * `expr' structure. Return the mode of
 * the address.
 *
 * This addr(esp) routine performs the following addressing decoding:
 *
 *	address		mode		flag		addr		base
 *	#n		S_IMMED		0		n		NULL
 *	label		s_type		----		s_addr		s_area
 *	[REG]		S_IND+icode	0		0		NULL
 *	[label]		S_INDM		----		s_addr		s_area
 *	offset[REG]	S_IND+icode	----		offset		----
 */
int
addr(struct expr *esp)
{
	int c, mode, indx;
	char *p;

	/* fix order of '<', '>', and '#' */
	p = ip;
	if (((c = getnb()) == '<') || (c == '>')) {
		p = ip-1;
		if (getnb() == '#') {
			*p = *(ip-1);
			*(ip-1) = c;
		}
	}
	ip = p;

	if ((c = getnb()) == '#') {
		expr(esp, 0);
		esp->e_mode = S_IMMED;
#if 0
                /* ljm - leading digit is used for offset for dd(ix|iy|sp) */
        } else if ((c == '-') || ((c >= '0') && (c <= '9'))) {
          unget(c);
          expr(esp, 0);
          esp->e_mode = S_IMMED;
#endif
	} else
	if (c == LFIND) {
          /* ljm comment -
           *      '(' number ')'   
           *  or  '(' register=[hl,ix,iy,sp,bc,de] ')'
           *     ref to memory, scan the next 'symbol' to see if
           *     it is a register or an absolute address
           */
		if ((indx = admode(R8)) != 0) {
			mode = S_INDB;
		} else
		if ((indx = admode(R8X)) != 0) {
			mode = S_R8X;
			aerr();
		} else
                if ((indx = admode(R16AF_ALT)) != 0) {
                        mode = S_R16AF_ALT;
			aerr();
		} else
		if ((indx = admode(R16AF)) != 0) {
			mode = S_R16AF;
			aerr();
		} else
		if ((indx = admode(R16)) != 0) {
			mode = S_INDR;
		} else {
			mode = S_INDM;
			expr(esp, 0);
			esp->e_mode = mode;
		}
		if (indx) {
                        esp->e_mode = (mode + indx)&0xFF;
			esp->e_base.e_ap = NULL;
		}
                /* ljm comment -
                 *   flag an error if the closing paren is absent
                 */
		if ((c = getnb()) != RTIND) {
                        xerr('q', "Missing ')'.");
		}
	} else {
		unget(c);
          /* ljm -
           *   cases:
           *     register
           *     symbol
           *     symbol(register)
           *     number
           *     number(register)
           *
           * scan the list(s) of registers to see if the
           * name matches the name of one of the processor
           * registers
           */
		if ((indx = admode(R8)) != 0) {
			mode = S_R8;
		} else
		if ((indx = admode(R8X)) != 0) {
			mode = S_R8X;
		} else
                if ((indx = admode(R16AF_ALT)) != 0) {
                        mode = S_R16AF_ALT;
		} else
		if ((indx = admode(R16AF)) != 0) {
			mode = S_R16AF;
		} else
                if ((indx = admode(R16_ALT)) != 0) {
                        mode = S_R16_ALT;
		} else
		if ((indx = admode(R16)) != 0) {
			mode = S_R16;
		} else
                if ((indx = admode(R32_JKHL)) != 0) {
                        mode = S_R32_JKHL;
		} else
                if ((indx = admode(R32_BCDE)) != 0) {
                        mode = S_R32_BCDE;
		} else
                if ((indx = admode(RXPC)) != 0) {
                        mode = S_RXPC;
		} else {
			mode = S_USER;
			expr(esp, 0);
			esp->e_mode = mode;
		}
		if (indx) {
			esp->e_addr = indx&0xFF;
			esp->e_mode = mode;
			esp->e_base.e_ap = NULL;
		}
		if ((c = getnb()) == LFIND) {		  
			indx = admode(R16);
                        if ((indx&0xFF)==IX || (indx&0xFF)==IY ||
                            (indx&0xFF)==SP)
                        {
                          esp->e_mode = S_INDR + (indx&0xFF);
                        } else if ( (indx&0xFF)==HL ) {
                          esp->e_mode = S_IDHL_OFFSET;
			} else {
				xerr('a', "BC, DE, HL, SP, IX, or IY required.");
			}
			if ((c = getnb()) != RTIND)
				xerr('q', "Missing ')'.");
		} else {
			unget(c);
		}
	}
	return (esp->e_mode);
}

/*
 * When building a table that has variations of a common
 * symbol always start with the most complex symbol first.
 * for example if x, x+, and x++ are in the same table
 * the order should be x++, x+, and then x.  The search
 * order is then most to least complex.
 */

/*
 * When searching symbol tables that contain characters
 * not of type LTR16, eg with '-' or '+', always search
 * the more complex symbol tables first. For example:
 * searching for x+ will match the first part of x++,
 * a false match if the table with x+ is searched
 * before the table with x++.
 */

/*
 * Enter admode() to search a specific addressing mode table
 * for a match. Return the addressing value on a match or
 * zero for no match.
 */
int
admode(struct adsym *sp)
{
	char *ptr;
	int i;
	char *ips;

	ips = ip;
	unget(getnb());

	i = 0;
	while ( *(ptr = &sp[i].a_str[0]) ) {
		if (srch(ptr)) {
			return(sp[i].a_val);
		}
		i++;
	}
	ip = ips;
	return(0);
}

/*
 *      srch --- does string match ?
 */
int
srch(char *str)
{
	char *ptr;
	ptr = ip;

	while (*ptr && *str) {
		if (ccase[*ptr & 0x007F] != ccase[*str & 0x007F])
			break;
		ptr++;
		str++;
	}
	if (ccase[*ptr & 0x007F] == ccase[*str & 0x007F]) {
		ip = ptr;
		return(1);
	}

	if (!*str) {
		if (!(ctype[*ptr & 0x007F] & LTR16)) {
			ip = ptr;
			return(1);
		}
	}
	return(0);
}

/*
 * Registers
 */

struct	adsym	R8[] = {
    {	"b",	B|0400	},
    {	"c",	C|0400	},
    {	"d",	D|0400	},
    {	"e",	E|0400	},
    {	"h",	H|0400	},
    {	"l",	L|0400	},
    {	"a",	A|0400	},
    {	"",	0000	}
};

struct	adsym	R8X[] = {
    {	"eir",	EIR|0400},
    {	"iir",	IIR|0400},
    {	"",	0000	}
};

struct  adsym   R8IP[] = {
    {   "ip",   IP|0400	},
    {	"",	0000	}
};

struct	adsym	R16AF[] = {
    {	"af",	AF|0400	},
    {	"",	0000	}
};

struct  adsym   R16AF_ALT[] = {
    {	"af'",	AF|0400	},
    {	"",	0000	}
};

struct	adsym	R16[] = {
    {	"bc",	BC|0400	},
    {	"de",	DE|0400	},
    {	"hl",	HL|0400	},
    {	"sp",	SP|0400	},
    {	"ix",	IX|0400	},
    {	"iy",	IY|0400	},
    {	"",	0000	}
};

struct  adsym   R16_ALT[] = {
    {	"bc'",	BC|0400	},
    {	"de'",	DE|0400	},
    {	"hl'",	HL|0400	},
    {   "",     0000 }
};

struct  adsym   R32_BCDE[] = {
  {   "bcde",   BCDE|0400 },
  {   "",       0000      }
};

struct  adsym   R32_JKHL[] = {
  {   "jkhl",   JKHL|0400 },
  {   "",       0000      }
};

struct  adsym   RXPC[] = {
  {   "xpc",    1|0400  },
  {   "",       0000    }
};

/*
 * Conditional definitions
 */

struct	adsym	CND[] = {
    {	"NZ",	NZ|0400	},
    {	"Z",	Z |0400	},
    {	"NC",	NC|0400	},
    {	"C",	CS|0400	},
    {   "LZ",   PO|0400 },
    {   "LO",   PE|0400 },
    {	"P",	P |0400	},
    {	"M",	M |0400	},
    {	"",	0000	}
};

struct  adsym   ALT_CND[] = {
    {   "GT",   CC_GT|0400  },
    {   "GTU",  CC_GTU|0400 },
    {   "LT",   CC_LT|0400  },
    {   "V",    CC_V |0400  },
    {   "NZ",   CC_NZ|0400  },
    {   "Z",    CC_Z |0400  },
    {   "NC",   CC_NC|0400  },
    {   "C",    CC_C |0400  },
    {   "",     0000        }
};
